AIR for Facebook UWP - anything but the bloated official client, eh?
(All About Windows Phone)

The canny way to use Facebook on Windows 10 Mobile is, of course, to use the web site in Edge. No bloated 100MB client, no wastage, and almost full functionality. But there are ways to use the web site without actually using the browser. I`m talking about web wrappers, of course, applications which provide a customised front end to the Facebook web experience. SlimSocial has been my `go to` here because it adds the option of a dark theme, but this new `AIR for Facebook` is another valid option, providing a proper Start screen application shortcut and some useful in-site shortcuts.